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PCB Manufacturing Process: A Comprehensive Guide

pcb manufacturing process

The recent COVID-19 pandemic did impact the global PCB manufacturing industry. However, thanks to the increasing demand for electronic products and developments in the PCB manufacturing process, the market is now bouncing back rapidly.

The global PCB market size is projected to reach $86170 million by 2026, from $70920 million in 2020, at a CAGR ( Compound Annual Growth Rate) of  3.3% from 2021 to 2026. 

As a business owner or retailer, knowing the printed circuit board manufacturing process is necessary. It can help you choose a suitable PCB manufacturer for your next project.

In this detailed guide, we will discuss the PCB manufacturing process, including designing, testing, and assembly, among other things. 

Let’s start with the basics.

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    What is PCB?

    PCB stands for Printed Circuit Board. It mechanically supports and electrically connects various components in a circuit.

    The basic printed circuit board design includes a flat sheet of insulating material and a layer of copper foil, laminated onto a non-conductive substrate (usually fiberglass).

    The PCB circuit board uses conductive pathways, tracks, or signal traces etched from copper sheets to connect the circuit board components.

    The conductive material of choice for PCBs is copper. These circuit boards also have a protective coating called a solder mask or solder resist, which protects the circuit board from short circuits and soldering errors.

    PCBs are the foundational block of a majority of modern electronic devices. Semiconductors, resistors, capacitors, and diodes are all mounted to communicate with each other through the printed circuit board.

    With the development of advanced technology in recent years, the PCB manufacturing process can now be fully automated. It consists of four steps: designing, manufacturing, assembly, and testing.

    PCB Design Process

    As mentioned earlier, designing is the first step in PCB manufacturing. Ordinarily, the PCB design process involves the following steps.

    1. Schematic Design

    The schematic design, also called a schematic diagram, is essentially a blueprint for designing the PCB.

    It provides a logical representation of different PCB components, traces, and electronic circuitry.

    Each component that is used on a circuit board has an identifying symbol that represents it on the schematic board.

    ● You will need a clear idea of what should go into your PCB design as the engineer will design the schematic diagram based on your technical requirements
    ● The designer will use logical symbols and notations for each component as per industry standards
    ● Each symbol will have one or more pins connected by lines called nets to create a schematic design using CAD (Computer-Aided Design) software, specifically meant for PCB designing

    2. PCB Layout Planning

    Once all of the symbols are placed and the nets are connected in the schematic, the circuit board is ready for physical design in a process called “PCB layout”, which involves:

    ● Creating models of the physical components within the layout tools
    ● Ensuring that the nets do not come in contact with each other or they will be shortened once the printed circuit board is built
    ● Setting up the physical shape and structure of the PCB in the layout database

    3. Component Placement Planning

    Once the virtual schematic diagram is ready, the next step in the PCB design process is planning PCB component placement.

    It will help in determining how many PCB layers you need, among other technical specifications.

    Component placing also ensures that the manufacture of the board takes place without errors. This lowers the overall production costs of building a printed circuit board.

    The designer will place the component footprints in the following order.

    ● Fixed PCB components like connectors and switches get placed in the layout database first. This ensures that they mate correctly with plugs or openings in the system enclosure
    ● Next, critical PCB components like microprocessors, memory chips, and power supplies are laid next to fixed components
    ● Supporting PCB components like capacitors, resistors, and inductors will be placed close to the critical parts
    ● Finally, the technician will lay down PCB components like terminating resistors or bulk decoupling capacitors. They may not necessarily support a critical part directly but are essential in PCB manufacturing

    4. Connection Routing

    After the PCB components are in place, the designer will connect the components with trace routing.

    The trace routing will transform into meta connection during the PCB fabrication process.

    The four most common trace routing methods include:

    Manual Routing: The designer picks one net and traces its route manually. This is done using straight or curved lines, right angles, or placing a hole in the board called a via to transition to another layer.

    Semi-Automated Routing: Using the semi-automated trace routing features of the CAD application, the designer will route a net or groups of the net.

    Auto-Interactive Routing: A combination of manual and automated tracing, this feature allows the designer to create customized routes manually. But the CAD application traces them as per signal integrity rules.

    Batch Auto-Routing: The designer will trace all the routes manually and set routing rules. They will pre-route the areas by hand first and then they will connect the nets using an auto-router.

    5. Designing the Circuit Board

    At this stage in the PCB designing process, the designer will plan and lay down the number of layers, circuit board dimensions, and the PCB components using a specialized application called Electronic Design Automation (EDA).

    ● The designer will suggest PCB designing changes, such as using surface mounting instead of through-hole technology based on your technical specifications and requirements
    ● After finalizing the printed circuit board, the designer will export the files to Gerber or CAD format as per industry standards

    6. Final Manufacturing Files

    The final stage in the PCB design process involves exporting the Gerber or CAD files for actual manufacturing. You can send these files to your PCB board manufacturer along with the required set of instructions.

    PCB Manufacturing Process

    After the PCB design is approved and the manufacturer receives your final manufacturing files, the PCB fabrication or manufacturing begins. This is where your virtual circuit board design turns into a physical printed circuit board.

    1. Imaging the Design

    Imaging the Design

    After multiple checks, your PCB board design is ready to print. Your PCB board manufacturer uses a specialized printer called a plotter printer to convert circuit board design files into films. These films are like the photo negatives of your schematic diagram.

    When printed, the inside layers of the PCB has two ink colors:

    ● Black ink representing copper traces and circuits of the PCB
    ● Clear ink representing the non-conductive areas of the PCB like the fiberglass base

    The outer layer has:

    ● Clear ink indicating copper pathways
    ● Black ink denoting the area where the copper will be etched away

    The films also have a registration hole issued for aligning printed circuit boards during the later stages of the manufacturing process. The films will be stored in a safe place to avoid unwarranted contact.

    2. Printing Inner Layers on Copper

    Printing Inner Layers on Copper

    This step in the PCB manufacturing process marks the beginning of making the actual PCB. The process starts with the basic form of a PCB, which comprises a laminate board made from the substrate material. The substrate material usually is epoxy resin and glass fiber.

    ● The PCB design is printed onto the laminate board
    ● Copper is pre-bonded on both sides of the laminate board
    ● Copper is then etched away, revealing the PCB design as per the film
    ● Next, the laminate board gets covered with a photo-sensitive film called the resist

    3. UV Light Blasting

    UV Light Blasting

    The resist consists of a layer of photo-reactive chemicals. The PCB manufacturers expose the resist-covered laminate boards to Ultraviolet or UV light, which hardens the layer of photo-reactive chemicals.

    ● The UV light passes through the translucent parts of the film, hardening the photoresist
    ● But, UV light can’t harden the areas with black ink
    ● Only hardened areas are kept as copper pathways, the rest of the board is slated away
    ● The board is washed with an alkaline solution to remove photoresist leftovers
    ● A final pressure wash removes any residues
    ● The board is dried
    ● A technician examines the board for errors before moving to the next step

    The purpose of using photoresist and UV light blasting is to ensure the actual PCB fabrication matches perfectly with the schematic blueprints.

    4. Etching the Inner Layer

    Etching the Inner Layer

    In PCB manufacture, clean lines matter. As such, this PCB manufacturing process removes the extra copper from the circuit board. An errant speck of dirt might otherwise cause a circuit to be short or remain open. After this step, you will have only the copper required to make the PCBs.

    ● Usually, the inner layer of copper will be removed by chemical etching
    ● The photoresist keeps the necessary copper on the board safe from etching
    ● The time and solvent required for etching may vary depending on the size of the boards
    ● Larger boards often require more time and/or solvent

    5. Layer Alignment

    Layer Alignment

    After cleaning, the laminate boards are ready for layer alignment. Generally, PCB manufacturers use the optical punch, a specialized machine that drives a pin through the registration holes to align inner and outer layers.

    6. Optical Inspection

    Optical Inspection

    When the layers are clean and ready to go, they require the right alignment. Thus, the technician places the layers into an optical punch machine.

    This is referred to as optical inspection. It ensures the PCBs are devoid of any defects because there is no room for error correction once the layers come together.

    ● The designer will use an Automated Optical Inspection (AOI) machine for inspection
    ● The AOI machine compares the PCBs with original schematic diagrams
    ● The AOI machine scans the layers with a laser sensor and makes an electronic comparison
    ● The PCB manufacturer discards the defective circuit boards at this stage
    ● The process is repeated for the outer layers after imaging and etching them

    7. Laminating & Pressing the Layers

    Laminating and Pressing the Layers

    At this stage in the printed circuit board manufacturing, the PCB starts taking shape. The defect-free layers are fused and laminated together to create the PCBs in the following two steps.

    Lay Up or Layer Up

    This process sandwiches the outer layer of PCBs (made from fiberglass pre-coated with epoxy resin) and the layer of thin copper foil (with etchings for the copper traces). The process is carried out on a specialized press table using metal clamps.

    ● The operator uses a specialized pin to fit each layer onto the table
    ● First, the operator places a layer of pre-coated epoxy resin, called prepreg, on the table’s alignment basin
    ● Next, they place a layer of the substrate over the pre-impregnated epoxy resin
    ● A copper foil layer is placed over the layer of the substrate
    ● More sheets of pre-impregnated resins get placed over the copper foil layer
    ● The stack gets finished off with a copper or aluminum press plate
    ● The operator makes sure to fit the stack perfectly to prevent shifting during the alignment
    ● Now, the stack is ready for bonding

    Lamination or Bonding

    Before bonding, the operator takes the stack to a mechanical press to fuse the layers.

    ● The operator places the stack on the laminate press
    ● The bonding press computer controls the laminate press
    ● The computer will heat press plates and apply pressure as per calibrations, fusing the PCB layers
    ● After removing the top press plate and the pins, the technician will pull out the printed circuit board

    8. Drilling

    Drilling

    Considered the most critical step in the PCB manufacturing process, drilling establishes the foundation for vias and the connectivity between different PCB layers.

    All components slated to come later, such as copper-linking via holes and leaded aspects, rely on the exactness of precision drill holes.

    PCB drilling requires the highest precision because even the tiniest error can result in considerable financial losses.

    That’s why leading professional China PCB manufacturers tend to use computer-controlled PCB drilling machines. These machines can drill holes as small as 100 microns in diameter, using air-driven spindles that turn at 150,000 RPM. Drilling also requires time as an average PCB has over one hundred drilling points.

    ● Before drilling, an X-ray locator locates the drill spots
    ● A board of buffer material is placed beneath the drill target to ensure clean drilling
    ● First, registration or guiding holes are drilled to secure the PCB stack
    ● A computer-controlled machine drills the target using the original design as the guide
    ● After the drilling, the additional layer of copper around the edges is removed by profiling

    9. PCB Plating

    PCB Plating

    After drilling, the next step is plating. PCB plating is the process of filling the drilled holes with copper to allow the current to pass from the surface of the board to the inner layers, between two layers, or between two surfaces. The process involves a series of chemical baths.

    ● Cleaning the PCB panel thoroughly
    ● Placing the panel in a series of chemical baths that deposit a thin layer of copper, about one micron thick
    ● Controlling the PCB plating process using computers

    10. Outer Layer Imaging

    Outer Layer Imaging

    Just like in step two, this step also involves applying another photoresist to the PCB panel. However, the photoresist gets applied to only the outer layer for imaging. The process takes place in a sterile environment.

    ● Pins secure black ink transparencies and prevent misalignment
    ● The PCB panel, after coating with the photoresist, passes into the yellow room
    ● The UV light blast hardens the photoresist
    ● Removing the unhardened resist that is protected by black ink

    11. Outer Layer Etching

    Outer Layer Etching

    Outer layer etching prepares the PCB panel for AOI (Automated Optical Inspection) and soldering. During this process, unwarranted copper from the outer layers gets removed.

    ● A layer of copper is applied using the electroplating method
    ● After initial copper baths, tin electroplating is used to protect copper in the critical area
    ● The PCB board undergoes Automated Optical Inspection (AOI) to ensure the copper layer meets the desired specifications

    12. Solder Mask Application

    Solder Mask Application

    Solder mask application is necessary as it adds a protective layer on exterior surfaces of a printed circuit board, preparing it for the soldering process. It essentially masks areas that don’t require soldering.

    ● PCB panel is cleaned to remove impurities or unwarranted copper
    ● An ink epoxy and solder mask film are applied on the surface
    ● UV light blasting is used to indicate the areas that don’t need soldering
    ● The solder mask is removed from unwarranted areas
    ● The circuit board goes into an oven to cure the solder mask

    13. Silk Screening

    Silk Screening

    Silk screening is where all the information is printed directly on the board with an ink-jet printer. It usually includes:

    ● Company ID
    ● Warning labels
    ● PCB Manufacturer’s logo or symbols
    ● Component numbers
    ● Pin locators and other markings

    14. Surface Finishing

    Surface Finishing

    The nearly complete PCB panels require a coating of conductive material, generally as per the customer’s specifications. This adds extra soldier-ability to the PCB. This process results in a surface finish.

    Here is a list of conductive materials used for surface finishing with their benefits and drawbacks.

    a) Immersion Silver:

    Benefits

    ● Low signal loss
    ● No presence of lead
    ● RoHS compliant
    ● Reworkable surface for manufacturers who want to press-fit pin inserts into the PCB

    Drawbacks

    ● The finish can oxidize and tarnish. However strong anti-surface tarnish can solve this problem
    ● In cases where the surface is not protected, immersion silver has a short shelf life
    ● Not suitable for multiple assembly processes

    b) Gold:

    Benefits

    ● Durable, as it has a two-layer metallic coating that protects the surface of the PCB
    ● Lead-free, meaning that it is environmentally-friendly
    ● Long shelf-life
    ● RoHS compliant

    Drawbacks

    ● Expensive in comparison to other surface finishes as it follows a complicated process, and is not re-workable.

    c) Electroless Nickel Immersion Gold (ENIG):

    Benefits

    ● Very common
    ● Long shelf-life
    ● RoHS compliant

    Drawbacks

    ● Relatively more expensive than most other finishes

    d) Hot Air Solder Leveling (HASL):

    Benefits

    ● Cost-effective
    ● long-lasting
    ● Reworkable
    ● Allows a large processing window

    Drawbacks

    ● Contains lead
    ● Not RoHS compliant

    e) Lead-free HASL:

    Benefits

    ● Cost-effective
    ● Lead-free
    ● RoHS compliant
    ● Reworkable

    Drawbacks

    ● Not good for multiple reflow/assembly processes
    ● The process requires the use of a carcinogen called Thiourea
    ● Difficult to measure the thickness

    f) Immersion Tin (ISn):

    Benefits

    ● Popular for press-fit applications
    ● Tight tolerances for holes
    ● RoHS compliant

    Drawbacks

    ● Can cause soldering problems

    g) Organic Solderability Preservative (OSP):

    Benefits

    ● RoHS compliant
    ● Cost-effective

    Drawbacks

    ● Short shelf life

    h) Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG):

    Benefits

    ● High solder strength
    ● Reduced corrosion

    Drawbacks

    ● Requires careful processing for optimal performance
    ● Less cost-effective compared to finishes that don’t use gold or palladium
    For designers and manufacturers, selecting the best finish needs the balancing of the available options while factoring in the cost of the materials and performance requirements.

    15. Testing

    Testing

    PCB testing is also a critical step in the manufacturing process. Your PCB manufacturer will use different testing methods to ensure the PCBs are functional and confer to the original design specifications. We will cover the well-established PCB testing methods in detail later in the post.

    16. Profiling

    Profiling

    Profiling is essentially the last step in the PCB manufacturing process. Until this sage, the printed circuit boards are one construction panel. Using the original design files, the PCBs get sliced into individual boards. There are two most common ways to split PCB boards:

    Scoring: Also known as routing out, this method includes cutting several small tabs around the edges of the circuit boards

    V-Groove: In this method, the CNC machine makes V-shaped cuts along the side of the PCB boards

    You can break off the PCB boards easily after profiling, irrespective of the method used.

    17. Final Quality Check

    Final Quality Check

    After profiling, each printed circuit board undergoes a final visual inspection and quality check. The manufacturer will package and ship error-free PCBs after the final examination.

    The following checks help identify error-free and functional PCBs:

    ● The repairing and retesting of all boards failing PCB inspections
    ● Perfectly aligning all PCBs with their original design specifications
    ● Checking and maintaining a sterile environment to prevent contamination and errors
    ● Checking all finished PCBs for burrs or sharp edges
    ● Perfectly matching the hole sizes on all PCB layers
    ● Conferring the hole sizes to the design specifications

    18. Packaging and Shipping

    Packaging and Shipping

    This stage is about packaging and shipping the PCBs to their intended destinations. The standard packaging design protects PCBs from dust and other environmental factors. However, packaging may change based on the customer’s specifications and also the PCB manufacturer.

    PCB Assembly Process

    PCB assembly or fabrication process is different from the PCB manufacturing process. While manufacturing is about making the PCB board itself, the fabrication involves soldering the PCB components onto the board.

    Before the Assembly Process

    There are preparatory steps that take place before the PCB assembly process happens. This is essential for PCB manufacturers as it allows them to access the functionality of a PCB design before it is fully assembled.

    First, the assembly team goes through the design-specific notes and requirements. Once the assessment is complete, any potential redundant or problematic features are addressed.

    By identifying these issues before the assembly begins, then the team will cut down on excessive costs as they will easily eliminate unforeseen expenses.

    The Assembly Process

    A typical PCB assembly process consists of the following steps:

    1. Solder Paste Application

    Solder Paste Application

    The first step in the PCB assembly process is the application of solder paste to the circuit board. The solder paste is applied to areas where PCB components need to be soldered. These areas are called solder pads. Usually, a thin stainless-steel stencil is used to apply the paste.

    Solder Paste

    The solder paste consists of tiny grains of solder mixed with the flux. The typical composition of solder includes 96.5% tin, 3% silver, and 0.5% copper. The flux is a chemical that helps solder melt and also sticks to the surface.

    Application Process

    ● The process takes place on a professional PCB assembly line
    ● The PCB and solder stencil is held together by a mechanical fixture
    ● The solder paste is applied to the desired areas using an applicator
    ● The machine spreads the solder paste across the stencil with precision
    ● After the application is finished, the stencil is removed

    2. Pick and Place

    Pick and Place

    This step of the printed circuit board assembly process requires a pick-and-place machine. It is a robotic device with the highest placement precision.

    Traditionally, technicians used a pair of tweezers to pick and place PCB components on the board. However, the practice is no longer in use.

    The robotic pick-and-place machines are faster, more accurate, and can work virtually 24/7. Here is how a pick-and-place machine works:

    ● The machine picks up the PCB board using a vacuum grip
    ● The device starts placing surface mount components (SMCs) or Surface Mount Devices (SMDs) on the board
    ● The SMDs are placed as per the preprogrammed locations derived from the original printed circuit board design
    ● If the board is to be wave soldered, the machine may add small dots of glue to secure the SMDs

    3. Reflow Soldering Process

    Reflow Soldering Process

    After placing the PCB components on the board, the circuit board moves to the soldering area. The reflow soldering process involves pre-heating the components and solder paste and cooling it down. It attaches the SMDs to the PCB board without the risk of any damage.

    ● The PCB board is placed on a conveyor belt
    ● The conveyor belt moves through a reflow oven
    ● The oven gradually heats the PCBs to 250 degrees Celsius or 480 degrees Fahrenheit
    ● The PCBs continue to move through the oven as the solder melts
    ● Then the PCBs pass through coolers where the solder cools down gradually
    ● As the solder cools, it solidifies, creating a permanent solder joint between SMDs and the PCB board
    ● The stenciling and reflow processes are carried out twice for two-sided PCB assembly

    Sometimes, PCB board manufacturers may use a wave soldering machine instead of a reflow oven. However, the wave soldering process is almost outdated.

    4. Inspection

    Inspection

    Once the reflow process is complete, the PCBs must undergo a thorough inspection. The PCB manufacturer will check the PCBs for poor connection quality as misplaced SMDs can result in a short circuit.

    Here are the three most popular PCB inspection methods:

    a) X-Ray Inspection: As X-ray inspection can help you see through multiple layers, it’s a reliable method for checking complex and multilayered PCBs.

    b) Automated Optical Inspection (AOI): The AOI inspection uses a series of high-powered cameras to inspect various solders and SMDs on the PCBs. The AOI machine works fast and with higher accuracy, making this PCB quality check process very reliable and suitable for large PCB assembly batches.

    c) Manual Inspection: Despite automation, manual checks are still used, especially for small batches and less complicated PCB designs. Usually, technicians inspect the PCBs one by one for errors and misalignments. However, manual inspection is impractical for large quantities and PCBs with hundreds of SMDs.

    5. Plated Through Hole Component Insertion

    Plated Through Hole Component Insertion

    Most PCBs also include Plated Through Hole or PTH components, in addition to the SMDs. They are called PTH components because the lead is inserted into a copper-plated hole in the printed circuit board.

    A plated through-hole or PTH acts as a conductive conduit from one PCB layer to the other. It is drilled into the PCB board, and the inside is covered with a layer of conductive material like copper. PCB components need PTHs to send a signal across the PCB layers.

    Instead of soldering paste, the following methods are used in assembling PTH components.

    a) Manual Soldering: The technician will insert one PTH component into the suitable PTH manually.

    ● In a typical PCB assembly line, each technician inserts only one specific PTH component
    ● The PCBs pass from one station to another until the assembly is complete
    ● It is a time-consuming process

    b) Wave Soldering: It is an automated version of manual soldering, but involves a different soldering process. However, the process is not suitable for double-sided PCBs.

    ● PTH components are placed on the PCB board
    ● The circuit board moves to a specialized conveyor belt
    ● The conveyor belt passes through an oven which covers the bottom of the board with a wave of solder
    ● This pins all PTH components to the bottom of the circuit board

    6. Final Test and Inspection

    It is the last step in the PCB assembly process. The final inspection includes a “functional test” to ensure the boards are working correctly and adhere to the prescribed PCB quality standards. The test is conducted by stimulating the real-life electronic environment.

    If the PCBs fail the test, your PCB board manufacturer will have to either scrap or recycle them. If the PCBs pass the test, they are sent for packaging and shipping.

    Final Test and Inspection

    7. Packaging and Shipping

    Packaging and Shipping

    The PCBs are packed and shipped as specified by the customer or as per the manufacturer’s PCB quality standards.

    PCB Testing Process

    It is necessary to make sure the PCBs are in excellent working condition before shipping them off. So, all professional OEMs, including China PCB manufacturers, use several tests and different particular stages of production.

    What is PCB Testing?

    PCB testing is an integral part of the circuit board manufacturing process. It begins with understanding that the PCB is the foundation for any printed circuit assembly (PCA).

    Using different testing methods ensures the PCBs don’t drop dead or have a shortened life span. Some of the prevalent circuit board testing methods include the following.

    1) In-circuit Test

    In-circuit Test

    In-circuit testing (ICT), also called the bed-of-nails test, is probably the best PCB testing method. It powers up and actuates the individual circuitry on the PCB board by pressing the board down on a bed of probes.

    Advantages

    ● Higher consistency
    ● Test each PCB component individually
    ● Fully automated testing with zero human error
    ● Unlike AOI and flying probe tests, you can test ball grid array assemblies (BGAs)
    ● On-board verification of FPGAs
    ● Ability to check Bottom Terminated Components (BTC) solder integrity

    Disadvantages

    ● High initial cost
    ● Requires custom tooling and programming to fit the PCB board onto the ICT fixture or the bed of nails
    ● Customization is time-consuming
    ● Inability to test connectors and non-electrical components or components that work together
    ● Limited voltage range (0-5 volts)

    2) Automated Optical Inspection (AOI)

    Automated Optical Inspection

    Automated Optical Inspection (AOI) is essentially automated visual inspection of PCBs using HD cameras and high-end infrared, UV, and LED lighting systems.

    Advantages

    ● Completely contact-free PCB test
    ● Ability to detect a specific category of programmed defects like poor solder joints, missing or skewed components, and misshapen fillets
    ● You can do AOI at various stages of PCB assembly
    ● Ability to detect errors in PCB assemblies, not just individual boards
    ● Highly accurate results

    Disadvantages

    ● Inability to detect glue or seal defects
    ● Offers lower flexibility as you have to program each design change
    ● Detects only preprogrammed defects
    ● Offers no values in the development
    ● The team of operators or OEM manufacturers often lacks access to data from AOI systems
    ● You can’t program new defect tests into AOI systems remotely

    3) Flying Probe Test

    Flying Probe Test

    In a flying probe test, the test probes (usually two to six) move from one PCB test point to another as per the predefined software program. As the probes are moving, you can test points on both the top and bottom of the PCB board.

    Advantages

    ● Low cost
    ● Reduced development time
    ● Easy customization
    ● Suitable for several PCB assembly applications

    Disadvantages

    ● Slower compared to ICT and other PCB tests
    ● It may not be suitable for complicated PCB tests

    4) Burn-In Test

    During this test, PCB components are subject to extreme operating conditions such as high voltage and temperatures. It allows you to eliminate PCBs with weaker components.

    Advantages

    ● Helps determine product lifetime
    ● Helps build brand value by sending out only functional products

    Disadvantages

    ● Expensive
    ● Can cause mechanical and EOS/ESD damage to PCB components
    ● Inability to put the uniform distribution of stress on the device
    ● Voltage scaling and power consumption affect test reliability

    5) X-Ray Inspection

    This test uses an X-ray machine to inspect the PCBs, especially soldering connections, as they remain hidden from the AOI test. It is a reliable inspection for denser printed circuit boards.

    Advantages

    ● Reliable for finding faults in soldering connections
    ● Detects bubbles and voids (inadequately filled holes)
    ● Inspect parts under shield cover

    Disadvantages

    ● Requires specialized x-ray machines
    ● May lead to workplace hazards

    6) Functional Test

    This PCB testing essentially mimics the electronic environment the PCB is built for. The test uses functional tester interfaces. They are connected to the edge connector or a test-probe point of the PCB. The tester simulates the electronic environment for testing.

    Advantages

    ● Ability to identify functional defects
    ● Ability to determine DUT power consumption during operation
    ● Ability to identify problems with the analog and digital circuitry
    ● Ability to identify functional defects

    Disadvantages

    ● High cost
    ● Requires expensive high-speed testing equipment
    ● Requires a thorough understanding of the DUT and its working environment

    How to Choose the Right PCB Manufacturer

    Whether you are looking for a Chinese PCB manufacturer or a local manufacturer, it is necessary to find a reliable OEM (Original Equipment Manufacturer). Keeping the following points in mind can help you find such a manufacturer:

    1) Expertise

    Work with an experienced PCB board manufacturer, preferably someone with an excellent track record of designing and manufacturing the PCBs you want. Most professional PCB manufacturers are more than willing to share their portfolio.

    2) Production Capacity

    The PCB manufacturer also needs to have the ability to deliver the required quantities of PCBs on time. Be sure the manufacturer can match your order quantity and scale up or down the production as per your requirement.

    3) Quality Inspection Procedure

    Most professional manufacturers test the circuit boards and adhere to the international PCB quality standards. However, you should also find out which of the PCB tests mentioned in this guide your OEM can perform.

    4) Proven Track Record of On-Time Delivery

    The PCB manufacturing company also needs to have an excellent track record of on-time delivery. PCBs are an integral part of most electronic products. Therefore, any delay in PCB delivery will bring your entire production line to a halt.

    5) Flexibility and Responsiveness

    Perhaps the most critical factor is the ability of the PCB manufacturer to cooperate with you. The manufacturer needs to communicate with you proactively to avoid delays. The best PCB manufacturer is the one that strives to create a long-term relationship with you as a partner.

    FAQs

    Still have questions? While we can’t answer all your doubts in this post, here’s a list of a few FAQs that’ll help you understand critical aspects of PCBs.

    1) What Are the Main Components of a PCB?

    The main PCB components include:

    ● Battery
    ● Resistors
    ● LEDs
    ● Transistors
    ● Capacitors
    ● Inductors
    ● Diodes
    ● Potentiometers
    ● Silicon-Controlled Rectifier (SCR)
    ● Switches and Relays
    ● Integrated Circuits (ICs)
    ● Crystal Oscillators

    2) What Is the Standard PCB Thickness?

    Although there is no prescribed PCB thickness, most PCBs are 1.57 mm thick as this was the size Bakelite sheets had in the early days of PCB manufacturing. Other prevalent PCB thicknesses are 0.78mm and 2.36mm. However, the thickness may vary based on your requirements and your OEM.

    3) What Is a PCB Prototype?

    A PCB prototype is essentially a trial run before mass production. Your OEM will create prototypes using the design or blueprint and test them before starting the actual production.

    4) Why Do We Need PCB?

    PCBs are an integral part of almost all electronic products, save simple ones. The standardized compact design makes it easier to use them in electronics manufacturing. You can also replace damaged PCBs quickly. That’s why they are prevalent.

    5) How Long Does a PCB Board Last?

    Most PCBs can function for up to 10 years. However, the shelf-life depends on the PCB soldering and component quality.

    6) How Much Does a PCB Board Cost?

    The cost of PCB assembly varies based on their size, technical specifications, PCB quality standards, and the number of units you want to make. Usually, the higher number of PCB units will cost less as mass production for customized design can be cost-effective. However, you need to ask your PCB manufacturer for a detailed quote before placing your order.

    Conclusion

    The technical advances in the PCB manufacturing process have made it easier to create more compact, functional, and durable electronic products.

    Understanding the fundamentals of PCB assembly, manufacturing, and testing is the secret to unlocking the true potential of PCBs. Hopefully, this detailed guide will pave the way to your successful and reliable PCB production.

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